Telecommunication networks that support telephone service typically include, inter alia, local central office switches that route telephone calls, Operations Systems (OS) that perform telephone service provisioning and maintenance functions, and access networks (commonly referred to as the "local loop plant") that interconnect a telephone switch with terminal equipment located at a customer's premises. The endpoints of an access network, more particularly, interface with customer terminal equipment, e.g., a telephone station set, via respective telephone lines. A telephone switch in a central office includes an interface unit comprising line termination points, also called switch ports. Each line termination point that is in service (i.e., assigned to a subscriber) is associated, via the provisioning process, with a unique telephone number served by the telephone switch. The provisioning process also associates each such telephone number with a class of service, e.g., Plain Old Telephone Service (POTS). Thus, the association between a telephone line and a class of service is predicated on an association existing between the telephone line and a switch line termination port. Such associations are typically recorded in OS databases.
To provision telephone service at the premises of a particular customer, an available (unsubscribed) telephone line extending to those premises is associated with a particular switch port, a unique telephone number and a particular class of service. One major difficulty in the provisioning process is maintaining accurate data records detailing which telephone lines are connected to which customer equipment so as to be able to identify which telephone lines are in service (associated with a line termination point, as mentioned above) and which telephone lines are not in service (unsubscribed). This requirement is difficult to meet in view of the fact that the local loop plant is often being re-arranged responsive to requests for new service, in which telephone lines extending to new subscribers are interconnected (associated) via an access network with respective switch ports. If the accuracy of the data representing such associations is not maintained, then the provisioning of telephone service becomes labor intensive--i.e., dispatching a craftsperson to identify the telephone line that is present at a customer's premises.
Soft dial tone, also known as limited access dial tone, is a class of telephone service that may be associated with an unsubscribed telephone line. Such a service allows a user to place a telephone call via an unsubscribed telephone line to a restricted set of destination telephone numbers including, for example, 911 for emergency services and 611 for telephone subscription services. It can be appreciated then that soft dial tone service is not a billed service, and, because of that fact, telephone calls directed to a soft-dial-tone line are blocked at the central office switch.
As is well-known, a person may obtain telephone service by dialing the telephone number of the local telephone service bureau, for example 611, and interact with an agent of the local telephone company. As a result thereof, the agent creates a service order defining the requested service, which, in turn, causes a so-called work order to be created. The work order, which might take several days to complete, includes information that (a) identifies which unsubscribed telephone line is present at the identified premises, (b) associates the identified telephone line with a port in the associated local switch and (c) associates the port with a unique telephone number. Such associations are made electronically from an operations center using a so-called Recent Change command. Some associations in the local loop plant may be made remotely and electronically, while others are implemented manually by a craftsperson at the termination point.
As mentioned above, a person may order telephone service via an unsubscribed telephone line. One local telephone company (Bell South) provides soft dial tone on selected unsubscribed telephone lines so that a person may dial the telephone number of the service bureau, for example 611, from an unsubscribed telephone line to order telephone service. In such an instance, the provisioning process proceeds quickly and the dispatch of a craftsperson is generally not needed. However, a number of problems are associated with providing soft-dial-tone service to unsubscribed telephone lines. These problems include increased administration costs and inefficient use of switch ports, and result from associating each unsubscribed line with a respective telephone number. Moreover, soft-dial-tone service is not provided on all unsubscribed telephone lines. The reason for this is that, in a typical case, the number of unsubscribed telephone lines associated with a particular outside loop plant exceeds the number of available (idle) ports serving that loop plant and also exceeds the number of available telephone numbers. Accordingly, only unsubscribed lines connected to switch ports are accorded soft-dial-tone service.